Diffusion-mediated synthesis of high-quality organic–inorganic hybrid perovskite nanocrystals

Organic–inorganic hybrid perovskite nanocrystals (PNCs) (APbX3, A = formamidinium, methylammonium, X = Cl, Br, I) are semiconductor materials with important implications for fundamental research and optoelectronic applications. However, the development of hybrid PNCs lags behind their all-inorganic counterparts (CsPbX3), primarily due to their fast growth time (tens of seconds) caused by the uncontrollable kinetics of their synthesis. Here we present a diffusion-mediated synthesis approach by selecting lead precursors with desired solubility in the reaction solvent. Pb(SCN)2, which has limited solubility, serves as a lead reservoir, providing a continuous source of lead throughout the reaction process. This strategy significantly slows down the reaction kinetics. The synthesis time for hybrid PNCs can be drastically prolonged to 180 min, while maintaining the size-focusing stage. As a result, the diffusion-mediated kinetics enables the scalable synthesis of high-quality hybrid PNCs with high monodispersity and near-unity photoluminescence quantum yield. The high-quality hybrid PNCs obtained by this method will stimulate explorations into their properties and drive the development of efficient optoelectronic devices. A diffusion-mediated synthesis strategy for organic–inorganic hybrid perovskite nanocrystals is reported, which can substantially slow down the reaction kinetics, improving size uniformity and achieving near-unity photoluminescence quantum yield.